Antibody to fibrosis-related molecule and medical application thereof

ABSTRACT

The present invention provides an antibody to a fibrosis-related molecule and medical application thereof. The antibody of the present invention is an antibody that binds to CHL1 protein and an antibody that neutralizes the binding of the CHL1 protein to a fibroblast.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage of PCT/JP2017/043,348, filedDec. 1, 2017, which claims priority to JP 2016-234717, filed Dec. 2,2016.

The instant application contains a Sequence Listing which has beensubmitted in ASCII format via EFS-WEB and is hereby incorporated byreference in its entirety. Said ASCII copy, created on Apr. 21, 2021, isnamed sequence.txt and is 4,141 bytes.

TECHNICAL FIELD

The present invention relates to an antibody to a fibrosis-relatedmolecule and medical application thereof.

BACKGROUND ART

Inflammation is necessary as a repair process of tissue damage. However,inflammation may not disappear after the repair of the tissue. In suchinflammation, fibroblasts are activated so that the amount of collagenexcreted is elevated, leading to the risk of causing fibrosis of thetissue.

Tissue fibrosis is irreversible and cannot be treated. Therefore, it isimportant to prevent fibrosis from occurring. Thus, there exist needsfor an approach of diagnosing fibrosis or an approach of preventingfibrosis.

CHL1 is known as a cell adhesion molecule analogous to a brain neuralcell adhesion factor L1 (Non Patent Literature 1). However, itsphysiological functions are hardly known.

CITATION LIST Non Patent Literature

-   Non Patent Literature 1: MH Wei et al., Hum. Genet. 103, 39:    355-364, 1998

SUMMARY OF INVENTION Technical Problem

The present invention provides an antibody to a fibrosis-relatedmolecule and medical application thereof.

Solution to Problem

The present inventors have identified CHL1 as a factor specificallyexpressed at the acute phase and chronic phase of inflammation. Thepresent inventors have revealed that: CHL1 is presented on the membranesurface of fibroblasts; and secreted CHL1 binds to a non-immune andnon-epithelial non-hemocyte cell, such as a myofibroblast, of the laminapropria and a submucosal layer. The present inventors have also foundthat: an anti-CHL1 antibody delays tissue repair ascribable tofibroblasts at the acute phase of inflammation, and can suppressexcessive collagen production and the activity of fibroblasts at thechronic phase of inflammation. The present inventors have further foundthat the expression of CHL1 is sustained not only at the acute phase butat the chronic phase of inflammation, and found that the administrationof an anti-CHL1 antibody after the acute phase of inflammation causessuppression of collagen deposition and fibroblast activation.

Specifically, the present invention provides the following aspects:

[1] An antibody that binds to CHL1 protein, or an antigen-bindingfragment thereof, wherein the antibody or the antigen-binding fragmentthereof neutralizes the binding of the CHL1 protein to a non-immune andnon-epithelial non-hemocyte cell of the lamina propria and a submucosallayer.[2] An antibody that binds to CHL1 protein, or an antigen-bindingfragment thereof, wherein the antibody is (1) an antibody having a heavychain variable region having heavy chain CDR1 having the amino acidsequence set forth in SEQ ID NO: 1, heavy chain CDR2 having the aminoacid sequence set forth in SEQ ID NO: 2 and heavy chain CDR3 having theamino acid sequence set forth in SEQ ID NO: 3, and a light chainvariable region having light chain CDR1 having the amino acid sequenceset forth in SEQ ID NO: 5, light chain CDR2 having the amino acidsequence set forth in SEQ ID NO: 6 and light chain CDR3 having the aminoacid sequence set forth in SEQ ID NO: 7, or(2) an antibody that competes with the antibody (1) for binding to theCHL1 protein.[3] The antibody or the antigen-binding fragment thereof according to[2], wherein the antibody is (3) an antibody having a heavy chainvariable region having the amino acid sequence set forth in SEQ ID NO: 4and a light chain variable region having the amino acid sequence setforth in SEQ ID NO: 8, or (4) an antibody that competes with theantibody (3) for binding to the CHL1 protein.[4] A pharmaceutical composition for use in treating or preventingfibrosis in a tissue or an organ, comprising an antibody or anantigen-binding fragment thereof according to any of [1] to [3].[5] A pharmaceutical composition for use in suppressing the activity offibroblasts in a tissue or an organ, comprising an antibody or anantigen-binding fragment thereof according to any of [1] to [3].[6] A pharmaceutical composition for use in accelerating healing ofinflammation in an inflammatory tissue, comprising an antibody or anantigen-binding fragment thereof according to any of [1] to [3].[7] A method for analyzing the presence or absence of inflammation in atissue, comprising determining the presence of CHL1 protein in thetissue.[8] The method according to [7], wherein the detection of the presenceor absence of the CHL1 protein is performed using an antibody that bindsto CHL1 protein, or an antigen-binding fragment thereof.[9] The method according to [7], wherein the detection of the presenceor absence of the CHL1 protein is performed using an antibody or anantigen-binding fragment thereof according to any of [1] to [3].[10] A diagnostic drug for use in diagnosing the presence or absence ofinflammation in a tissue, comprising an antibody that binds to CHL1protein, or an antigen-binding fragment thereof.[11] A probe for the detection of fibrosis-inducing non-hemocyte cells,comprising CHL1 protein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing results of expression analysis using amicroarray. In the drawing, “Fibro” represents a fibroblast, “Mac”represents a macrophage, “BM Mac” represents a bone marrow macrophage,and “B” represents a B cell. In the drawing, “Normal” represents anormal fibroblast, “Acute” represents a fibroblast that induced acuteinflammation, and “Chronic” represents a fibroblast that induced chronicinflammation. FIG. 1 shows the expression of genes having a nameindicated on the right side of the drawing.

FIG. 2 is a diagram showing the expression level of CHL1 gene in variouscells.

FIG. 3 is a diagram showing that CHL1 is expressed on a cell membrane atthe time of inflammation.

FIG. 4 is a diagram showing the expression of the CHL1 protein at thechronic phase of inflammation and the expression of the CHL1 protein ina human Crohn disease large intestine sample.

FIG. 5 is a diagram showing the influence of CHL1-knockout (CHL1KO)mouse-derived fibroblasts on the repair of tissue damage.

FIG. 6 is a diagram showing the role of CHL1 in a dextran sodium sulfate(DSS)-induced enteritis model. FIG. 6A shows that the ability to repairenteritis is reduced in a CHL1KO mouse by using the body weight recoveryof the DSS-induced enteritis model as an index. FIG. 6B shows a largeintestine tissue image obtained by hematoxylin-eosin staining. In FIG.6B, the delayed reformation of epithelial cells is seen in the CHL1KOmouse. FIG. 6C shows that the degree of fibroblast activation is reducedin the CHL1KO mouse due to the expression of α smooth muscle actin inlarge intestine fibroblasts so that the recruitment of fibroblasts intoepithelial cells is delayed. FIG. 6C shows that the ability toaccumulate epithelial cells (stained with EpCAM) and fibroblasts(stained with aSMA) in an inflammatory tissue is reduced in the CHL1KOmouse.

FIG. 7 shows a photograph showing the localization (red; light gray inthe drawing) of cells that associate with the CHL1 protein at a fibrosissite (blue site of Azan staining; dark gray in the drawing) of thelamina propria or a submucosal tissue (FIG. 7, left) and the fractionsof cells (FIG. 7, right). In the drawing, the arrowheads depict areaswith marked fibrosis, which are consistent with the localization of thecell population that associates with the CHL1 protein.

FIG. 8 is a diagram showing that CHL1 binds to some cells of thefraction R3. CHL1 had an Fc tag, and the Fc tag was detected in thedrawing.

FIG. 9 is a diagram showing that a 336 antibody, a monoclonal antibodyto the CHL1 protein, recognizes the CHL1 protein expressed on cellsurface.

FIG. 10 is a diagram showing that the 336 antibody can neutralize thebinding of the CHL1 protein to a cell.

FIG. 11 is a diagram showing that the 336 antibody which can neutralizethe binding of the CHL1 protein to a cell delays body weight recovery atthe acute phase of inflammation (left graph of FIG. 11) and delays thehealing of the intestinal mucosa (right photographs of FIG. 11).

FIG. 12 is a diagram showing that the CHL1 protein is expressed in asustained manner in fibroblasts even at the chronic phase ofinflammation.

FIG. 13 is a diagram showing that the CHL1 protein is detected from theexcrement of enteritis models (acute and chronic).

FIG. 14 is a diagram showing that an antibody to CHL1 suppressescollagen deposition and fibroblast activation in a fibrosis inductionprocess at the chronic phase of inflammation.

DESCRIPTION OF EMBODIMENTS

In the present specification, the term “subject” may be a mammal and ispreferably a human. The subject may be a subject having tissueinflammation or having the risk of developing tissue fibrosis.

In the present specification, the term “inflammation” refers to theprotective response of a living tissue to a disorder. Tissues reportedlyinvolved in inflammation are usually terminal vascular beds, blood andconnective tissues. A cause is removed by a series of responses fortissue repair. In the present specification, the term “acuteinflammation” or “acute phase of inflammation” means inflammationinvolved in tissue repair, and the term “chronic inflammation” or“chronic phase of inflammation” means inflammation after the tissuerepair. In general, the acute inflammation clinically refers toinflammation within approximately 7 days from development of a disorderin a tissue, and the chronic inflammation clinically refers toinflammation that is sustained beyond 7 days (e.g., in months or inyears).

In the present specification, the term “fibrosis” means that an excessof collagen is deposited in a tissue due to chronic inflammation so thatthe tissue is hardened. In the process of fibrosis, fibroblasts aredifferentiated and matured into myofibroblasts, which then activelyproduce and secrete collagen. Then, the cells themselves disappear,resulting in fibrotic connective tissues. Since the process of fibrosisis inconspicuous, fibrotic disease may be found after progression of thefibrosis. However, the fibrotic disease is a disease that cannot betreated. Therefore, it is important to prevent the disease.

[yl]

In the present specification, the term “active fibroblasts” refer to acell population with the enhanced ability to produce collagen ascompared with the steady state, among fibroblasts. Examples thereofinclude a population containing myofibroblasts. The active fibroblastsare produced from fibroblasts at the acute phase and chronic phase ofinflammation.

In the present specification, the term “antibody” means animmunoglobulin and includes a polyclonal antibody and a monoclonalantibody. The antibody is preferably a monoclonal antibody. Examples ofthe origin of the antibody include, but are not particularly limited to,a nonhuman animal antibody, a nonhuman mammalian antibody, and a humanantibody. The antibody may be a chimeric antibody, a humanized antibody,or a human antibody. Also, the antibody may be a bispecific antibody.

The antibody assumes a structure where two heavy chains associate withtwo light chains. Each heavy chain consists of a heavy chain variableregion (VH), a heavy chain constant region (CH1), a hinge region, CH2,and CH3, and each light chain consists of a light chain variable region(VL) and a light chain constant region (CL).

In the present specification, the term “antigen-binding fragment” meansa portion of the antibody that maintains binding activity against theantigen. The antigen-binding fragment may comprise the heavy chainvariable region or the light chain variable region, or both, of theantibody of the present invention. The antigen-binding fragment may bechimerized or humanized. Examples of the antigen-binding fragmentinclude Fab, Fab′, F(ab′)₂, Fv, scFv (single-chain Fv), diabody, andsc(Fv)₂ (single-chain (Fv)₂). Such a fragment of the antibody can beobtained, for example, by treating the antibody with an enzyme, thoughthe obtainment of the fragment is not limited thereto. For example, theantibody can be digested with papain to obtain Fab. Alternatively, theantibody can be digested with pepsin to obtain F(ab′)₂, which can befurther reduced to obtain Fab′. In the present invention, such anantigen-binding fragment of the antibody can be used.

In the present specification, CHL1 is also called cell adhesion moleculeL1-like or L1 cell adhesion molecule 2. CHL1 has originally been knownas a molecule that is expressed in the brain and is causative ofintellectual impairment. CHL1 is considered to function in neuronalsynapses.

In the present specification, the term “antibody-drug conjugate” (ADC)means a conjugate of the antibody and a drug. The drug is delivered to atarget site through binding to the antibody and is capable of exertingfunctions at the delivery site. In ADC, the antibody and the drug may belinked via a linker. The design and preparation method of ADC are wellknown to those skilled in the art.

The present invention provides the following antibody or antigen-bindingfragment thereof:

[1] An antibody that binds to CHL1 protein, or an antigen-bindingfragment thereof, wherein the antibody or the antigen-binding fragmentthereof neutralizes the binding of the CHL1 protein to a fibroblast.

According to the present inventors, an antibody that can neutralize thebinding of CHL1 to a fibroblast was able to suppress collagen depositionand fibroblast activation in a tissue at the chronic phase ofinflammation. Thus, this antibody or antigen-binding fragment isconsidered to be able to suppress collagen deposition and fibroblastactivation in a tissue at the chronic phase of inflammation byneutralizing the binding of CHL1 to a fibroblast. In one embodiment,this antibody or antigen-binding fragment neutralizes the binding ofCHL1 to a non-immune and non-epithelial non-hemocyte cell (in thepresent specification, this cell is also referred to as a“fibrosis-inducing non-hemocyte cell”), such as a myofibroblast, of thelamina propria and a submucosal layer. Possible receptors of CHL1 areproteins including adhesion molecules such as integrin and vitronectin(Katic J, J Neurosci. 2014 Oct. 29; 34 (44): 14606-23. doi:10.1523/JNEUROSCI.3280-13.2014), and a serotonin receptor (Kleene R, JCell Sci. 2015 Dec. 15; 128 (24): 4642-52. doi: 10.1242/jcs.176941).

The present invention also provides

[2] an antibody that binds to CHL1 protein, or an antigen-bindingfragment thereof, wherein the antibody is (1) an antibody having a heavychain variable region having heavy chain CDR1 having the amino acidsequence set forth in SEQ ID NO: 1, heavy chain CDR2 having the aminoacid sequence set forth in SEQ ID NO: 2 and heavy chain CDR3 having theamino acid sequence set forth in SEQ ID NO: 3, and a light chainvariable region having light chain CDR1 having the amino acid sequenceset forth in SEQ ID NO: 5, light chain CDR2 having the amino acidsequence set forth in SEQ ID NO: 6 and light chain CDR3 having the aminoacid sequence set forth in SEQ ID NO: 7, or(2) an antibody that competes with the antibody (1) for binding to theCHL1 protein.

The present invention also provides

[3] the antibody or the antigen-binding fragment thereof according to[2], wherein the antibody is (3) an antibody having a heavy chainvariable region having the amino acid sequence set forth in SEQ ID NO: 4and a light chain variable region having the amino acid sequence setforth in SEQ ID NO: 8, or (4) an antibody that competes with theantibody (3) for binding to the CHL1 protein.

The antibody (1) or (3) can neutralize the binding of CHL1 to anon-immune and non-epithelial non-hemocyte cell, such as amyofibroblast, of the lamina propria and a submucosal layer. This isprobably because the antibody binds to the surface, to which the CHL1protein binds, of the non-immune and non-epithelial non-hemocyte cell,such as a myofibroblast, of the lamina propria and a submucosal layer,and causes steric hindrance ascribable to the antibody so that the CHL1protein can no longer bind to the fibroblast. Thus, the antibody—thatcompetes with the antibody (1) or (3) can also bind to the surface, towhich the CHL1 protein binds, of the non-immune and non-epithelialnon-hemocyte cell such as a myofibroblast, and cause steric hindrance,thereby neutralizing the binding of CHL1 to the non-immune andnon-epithelial non-hemocyte cell such as a myofibroblast. If necessary,whether or not to neutralize the binding of CHL1 to the non-immune andnon-epithelial non-hemocyte cell such as a myofibroblast may beconfirmed.

The present invention provides an antibody that competes with theantibody (1) or (3) for binding to the CHL1 protein, wherein theantibody is capable of neutralizing the binding of CHL1 to a non-immuneand non-epithelial non-hemocyte cell such as a myofibroblast.

The antibody of the present invention can reduce the activity offibroblasts, reduce collagen production, or suppress collagendeposition, in a tissue or an organ (particularly, a regioncharacterized by inflammation in a tissue or an organ inducinginflammation). The antibody of the present invention can thereby preventtissue or organ fibrosis in the tissue or the organ (particularly, aregion characterized by inflammation in a tissue or an organ inducinginflammation). Thus, t_([YM2]) he present invention provides acomposition or a pharmaceutical composition for use in reducing theactivity of fibroblasts, reducing collagen production, or suppressingcollagen deposition, comprising the antibody of the present invention.The present invention also provides a pharmaceutical composition for usein treating fibrotic disease, comprising the antibody of the presentinvention. The present invention also provides a pharmaceuticalcomposition for use in preventing tissue fibrosis in a tissue whereinflammation has occurred, comprising the antibody of the presentinvention. Examples of the tissue or the organ where inflammation hasoccurred include the intestines (e.g., the small intestine and the largeintestine). The pharmaceutical composition of the present invention iscapable of preventing tissue fibrosis in a tissue where chronicinflammation has occurred. Thus, the pharmaceutical composition of thepresent invention may be used for a tissue where chronic inflammationhas occurred, particularly, a tissue where chronic inflammation hasoccurred before completion of tissue fibrosis. Thus, in one embodiment,the pharmaceutical composition of the present invention can beadministered to a subject having chronic inflammation (particularly, asubject having chronic inflammation before completion of tissuefibrosis). The pharmaceutical composition of the present invention maybe used for preventing tissue or organ fibrosis in a tissue or an organbefore occurrence of inflammation (i.e., a tissue or an organ in thesteady state). In the present specification, the term “treatment”includes slowing of aggravation of symptoms, stopping of aggravation ofsymptoms, and improvement in symptom. In the present specification, aportion of the “organ” is also referred to as a “tissue”.

In one embodiment, the pharmaceutical composition of the presentinvention can be administered to a subject having an inflammatorydisease selected from inflammatory bowel diseases such as Crohn diseaseand ulcerative colitis.

As mentioned later, in a subject having inflammation, CHL1 is releasedinto a tissue, into a body fluid or into excrement. Thus, thepharmaceutical composition of the present invention may be administeredto a CHL1-positive subject.

A pharmaceutical composition or a medicament comprising the antibody ofthe present invention as an active ingredient can be formulated by apharmaceutical method known in the art. For example, the pharmaceuticalcomposition or the medicament of the present invention may comprise apharmaceutically acceptable excipient. The excipient can be an excipientthat may be appropriately administered for providing an effective amountof the antibody of the present invention serving as an active ingredientto a subject. In one embodiment, the pharmaceutical composition or themedicament of the present invention can be an injection. The injectableexcipient can be a sterile aqueous solution, for example, apharmaceutically acceptable buffer solution such as a Ringer's solution,a Hank's solution or saline, or an isotonic solution containing glucoseor any of other aids. Examples of the aid include alcohols such asethanol, polyalcohols such as polyethylene glycol, and nonionicsurfactants such as polysorbate 80. The aid can be added forformulation. Sesame oil, coconut oil or soybean oil can be used as aninjectable oily liquid, and benzyl benzoate or benzyl alcohol can beused as an aid. The pharmaceutical composition or the medicament of thepresent invention can be administered parenterally (e.g., intravenouslyor intraperitoneally) in the form of an injection.

Preparation of Antibody

The antibody can be prepared by a method well known to those skilled inthe art. Specifically, the polyclonal antibody can be obtained byimmunizing animals with the antigen and an adjuvant, and obtaining theplasma of the immunized animals. Alternatively, the antibody may beobtained by immunizing animals with the antigen and an adjuvant,obtaining B lymphocytes from the immunized animals, fusing the Blymphocytes with myeloma cells to form hybridomas, and cloning ahybridoma producing the desired antibody. In the immunization step, acell line (e.g., 293 cells or CHO cells) is forced to express theantigen, and animals may be immunized with the resulting cells. Sincethe CHL1 protein expressed in the cell line is exposed to cell surface,the immunized animals are capable of producing an antibody to the CHL1protein. Alternatively, cells expressing the CHL1 protein, preferablythe CHL1 protein, may be purified and used in the immunization ofanimals.

The chimeric antibody can be prepared by a method well known in the art.The chimeric antibody can be prepared, for example, by replacing theconstant regions of an antibody with the constant regions of a humanantibody. The humanized antibody comprises, for example, nonhumananimal-derived complementarity-determining regions (CDRs), humanantibody-derived framework regions and human antibody-derived constantregions. The humanized antibody can be obtained, for example, bygrafting the CDRs to a human antibody. The human antibody can beobtained, for example, by immunizing human antibody-producinggenetically modified mice with the antigen. The bispecific antibody isan antibody that can bind to two different epitopes or antigens, and canbe prepared by a method well known to those skilled in the art. Thebispecific antibody can be prepared, for example, by a method of furtherfusing cells producing two different antibodies to prepare hybridhybridomas, or by expressing a V_(H) region and a V_(L) region on onepolypeptide chain via a linker that is too short to form a pair betweenthese two regions, and forming a complex with another polypeptide chainhaving a V_(H) region and a V_(L) region complementary to the V_(H)region and the V_(L) region to be paired therewith.

The antibody that competes with a certain antibody for binding to theantigen can be confirmed by competition assay well known to thoseskilled in the art. In the competition assay, an antibody that can blockthe binding of the desired antibody, for example, by at least 20%,preferably at least 20 to 50%, more preferably at least 50%, can beregarded as an antibody that competes therewith for binding to the sameantigen. The competing antibody can be confirmed by cross-blockingassay, preferably competitive ELISA assay. In the cross-blocking assay,for example, a microtiter plate is coated with the antigen, and acandidate competing antibody is added to the plate, followed byincubation to form the binding between the antigen and the candidateantibody. Then, the desired antibody is labeled and then further addedto each well. The plate is incubated and washed, and the amount of thedesired antibody bound can be quantified to determine whether or not theantibody has competed. When the candidate antibody competes therewith,the amount of the label remaining in the well should be decreased.

The antibody that can neutralize the binding of the CHL1 protein to afibroblast can be confirmed on the basis of whether or not the antibodycompetes with CHL1 for binding to a non-immune and non-epithelialnon-hemocyte cell such as a myofibroblast. For example, as described inExamples mentioned later, when a fusion protein of the CHL1 proteinbound with a tag (e.g., an Fc tag) is allowed to bind to a non-immuneand non-epithelial non-hemocyte cell such as a myofibroblast, thebinding of the CHL1 protein to the cell can be detected using anantibody that binds to the tag. An antibody that can block this binding(binding of CHL1 to the non-immune and non-epithelial non-hemocyte cellsuch as a myofibroblast), for example, by at least 20%, preferably atleast 20 to 50%, more preferably at least 50%, can be regarded as anantibody that can neutralize the binding of the CHL1 protein to thenon-immune and non-epithelial non-hemocyte cell as a myofibroblast.

In another aspect, the present invention provides a method for analyzing(or testing) the presence or absence of inflammation in a tissue,comprising determining the presence (presence or absence) of CHL1protein in the tissue. According to the present inventors, the CHL1protein exhibited high expression in an inflammatory tissue. Accordingto the present inventors, the CHL1 protein was secreted from a tissuehaving inflammation and was able to be detected in the body fluid,particularly, excrement, of an individual. Thus, the determination ofthe presence or absence of the CHL1 protein in the tissue includes thedetermination of the presence of the CHL1 protein in an inflammatorytissue as well as the determination of the presence of the CHL1 proteinin a body fluid or excrement, secreted from the inflammatory tissue.

In one embodiment of the present invention, the presence of the CHL1protein can be detected using an antibody that binds to CHL1. In oneembodiment, the antibody may be the antibody of the present invention.In another embodiment, the presence of the CHL1 protein can bedetermined by measuring the mRNA level of CHL1. The mRNA level can bemeasured by a method well known to those skilled in the art, such asSouthern blotting or quantitative PCR.

In one aspect, the present invention provides a diagnostic drug or adiagnostic kit for use in diagnosing the presence or absence ofinflammation in a tissue, comprising an antibody that binds to CHL1protein, or an antigen-binding fragment thereof. The diagnostic kit mayfurther have an additional configuration in addition to the diagnosticdrug, and may have a manual that explains a method for diagnosinginflammation. In one aspect, the present invention provides a testingdrug or a testing kit for use in diagnosing the presence or absence ofinflammation in a tissue, comprising an antibody that binds to CHL1protein, or an antigen-binding fragment thereof. The testing kit mayfurther have an additional configuration in addition to the testingdrug, and may have a manual that explains a method for testinginflammation.

In one aspect of the present invention, the CHL1 protein binds to anon-immune and non-epithelial non-hemocyte cell such as a myofibroblast.Thus, the CHL1 protein can be used in the detection of myofibroblasts.For example, upon contact of the CHL1 protein bound with or without atag with a cell fraction containing myofibroblasts, the CHL1 proteinbinds to a myofibroblast. The myofibroblasts can be detected bydetecting the cell bound on its surface with the CHL1 protein by flowcytometry. Also, the myofibroblasts can be enriched or isolated bygating the cell bound on its surface with the CHL1 protein by flowcytometry. Thus, in one aspect, the present invention provides a probefor the detection of fibrosis-inducing non-hemocyte cells such asmyofibroblasts, comprising CHL1 protein. In one embodiment, the presentinvention provides a composition for use in enriching or isolatingmyofibroblasts, comprising CHL1 protein. In this context, the“enrichment” means the elevation of the ratio of fibrosis-inducingnon-hemocyte cells such as myofibroblasts to all cells, and the“isolation” means the substantial isolation of fibrosis-inducingnon-hemocyte cells such as myofibroblasts from other cells. The presentinvention also provides a cell population comprising fibrosis-inducingnon-hemocyte cells thus enriched or isolated using the probe fordetection. The cell population comprising fibrosis-inducing non-hemocytecells enriched or isolated using the probe for detection can be used in,for example, the detection of the neutralization of the interactionbetween CHL1 and a non-immune and non-epithelial non-hemocyte cell ofthe lamina propria and a submucosal layer by an antibody or the like.

In one aspect, the present invention provides a method for preventingfibrosis in an inflammatory tissue in a subject in need thereof,comprising administering the antibody of the present invention to thesubject. In one aspect, the present invention provides a method fordiagnosing the presence or absence of an inflammatory tissue in asubject having the inflammatory tissue or a subject having thepossibility of having the inflammatory tissue, comprising determiningthe presence of CHL1 protein in the tissue. In one aspect, the presentinvention provides a method for enriching or isolating myofibroblasts,comprising: contacting a probe comprising CHL1 protein with a cellfraction containing myofibroblasts; and separating cells bound with theCHL1 protein from unbound cells.

In one aspect, the present invention provides use of the antibody of thepresent invention in the manufacture of a composition or a medicamentfor use in reducing the activity of fibroblasts, reducing collagenproduction, or suppressing collagen deposition. In one aspect, thepresent invention provides use of the antibody of the present inventionin the manufacture of a medicament for use in suppressing the activityof fibroblasts in an inflammatory tissue. In one aspect, the presentinvention provides use of an antibody that binds to CHL1 protein in themanufacture of a diagnostic drug or a diagnostic kit for use indiagnosing the presence or absence of inflammation in a tissue.

EXAMPLES Example 1: Microarray Analysis in Activated Fibroblast

This Example is aimed at identifying a factor, gene expression of whichvaries in activated fibroblasts.

(A) COL1a2-GFP tg/+C57Bl/6 mice (kindly provided by prof. Inagaki, TokaiUniversity School of Medicine) were used. Untreated normal mice (in thedrawings, also abbreviated to “Normal”), mice on days 7 to 10 after freedrinking of 2.25 to 2.5% aqueous dextran sodium sulfate solution(Medical & Biological Laboratories Co., Ltd. MBL) (5 days) (in thedrawings, also abbreviated to “Acute”), and mice on days 70 to 90 after3 repetitions of acute enteritis at 2-week intervals (in the drawings,also abbreviated to “Chronic”) were dissected, and their lamina propriacells of the large intestine were isolated by treatment withethylenediaminetetraacetic acid and collagenase. The obtained cells werestained with antibodies and sorted using a cell sorter (FACS Aria IIIBecton, Dickinson and Company (BD)).

Fibroblasts (COL1a2-GFP-positive CD45-negative podoplanin-positive),macrophages (CD45-positive F480-positive CD11b-positive), B cells(CD45-positive CD19-positive B220-positive), and C57Bl/6 mouse-derivedbone marrow macrophages (BM Mac) induced from Recombinant Mouse M-CSF(carrier-free) (BioLegend, Inc.: 576404) were fractionated by a routinemethod.

The antibodies used in this Example were as follows.

TABLE 1 Product Distributor Antibody name No. BioLegend DyLIght 649Donkey anti-rabbit IgG 406406 CSTjapan Vimentin XR rabbit mAb (AlexaFluor ® 647 9856S conjugate) BioLegend Alexa Fluoro 647 anti-mouseCD326(EpCAM) 118211 Life Goat anti human IgG(H + L) secondary antibody,A21445 Technologies Alexa 647 conjugate Biolegend APC goat anti-Rat IgG405407 ebioscience F(ab) anti-mouse IgGeFluor660 50-4010 BD APC ratanti-mouse Ly6c 560595 Biolegend APC anti-mouse podoplanin 127410Biolegend APC anti-mouse F4/80 123115 Biolegend FITC anti mouse IgG2a407105 Biolegend FITC anti-mouse Ly-6C 128006 BD FITC-Rat anti-mouseCD103 557494 Biolegend PE anti-mouse podoplanin 127407 Biolegend PEanti-mouse F480 123110 Sigma Anti-Actin, α-Smooth Muscle - Cy3 ™antibody, C6198- Mouse monoclonal clone 1A4, purified from 100ULhybridoma cell culture Biolegend PE anti-mouse sca1 108107 Biolegend PEanti-mouse CD146 134703 BioLegend PECy7 anti-mouse CD146 134714 BD PECy7rat anti-mouse CD45 552848 Biolegend APC/Cy7 anti-mouse F480 123118Biolegend APC/Cy7 anti-mouse CD45 103115 Biolegend APC/Cy7 anti-mouseCD4 100414 Biolegend Pacific Blue anti-mouse CD19 115523 BiolegendPacific Blue Anti-mouse CD11b antibody 101224 Biolegend Pacific BlueAnti-mouse CD45 antibody 103126 Biolegend Pacific Blue anti-mouse CD90,2 105324

Then, RNA was purified using TRIZOL (Thermo Fisher Scientific Inc.) andSuperScript VILO (Thermo Fisher Scientific Inc.). The obtained RNA wasanalyzed using Agilent gene expression microarray according to themanufacturer's manual attached to the product. The reagents used in themicroarray were as follows.

TABLE 2 Agilent product No. Product name G4852A SurePrint G3 Mouse GEmicroarray kit 8 × 60K 5190-2305 Low Input Quick Amp Labeling Kit (1color) 5188-5242 Gene Expression Hybridization kit 5188-5282 RNA SpickIn Kit (1 color) 5188-5327 Gene Expression Wash pack G2534-60014 8 × 60KGasket slide for 8 × 60K array format

The results were as shown in FIG. 1. As shown in FIG. 1, Chl1 was ableto be identified as a factor strongly expressed only in fibroblasts atthe acute phase and chronic phase of induced inflammation.

Example 2: Verification of Tissue-Specific Expression of Chl1

Next, the expression of Chl1 was confirmed using various tissues orcells.

(B) The intestinal epithelium (EpCAM-positive CD45-negative),fibroblasts (COL1a2-GFP-positive CD45-negative podoplanin-positive),macrophages (F480-positive CD11b-positive), CD4-positive T cells, Bcells (CD19-positive B220-positive), and lamina propria cells of thelarge intestine (whole colon cells) were isolated in the same way asabove. RNA was purified from each cell using TRIZOL (Thermo FisherScientific Inc./Invitrogen: 15596018) and subsequentlyreverse-transcribed using VILO (Thermo Fisher ScientificInc./Invitrogen: 11755500). The expression analysis of Chl1 wasconducted using Universal Probe Library (Roche Life Science) andLightCycler™ 480 system (Roche Life Science). Comparison with theexpression of Gapdh is shown (n=3). The results were as shown in FIG. 2.

As shown in FIG. 2, Chl1 exhibited high expression in fibroblasts,particularly, fibroblasts at the acute phase (“Acute”) and chronic phase“Chronic” of induced inflammation. This suggested that Chl1 may bepreferably used as a marker for acute and chronic inflammation.

Example 3: Identification of Expression Site of Chl1

This Example showed that Chl1 is expressed on a cell membrane.

(C) Lamina propria cells of the large intestine were isolated fromnormal (day 0) wild-type C57Bl/6 mice and CHL1-knockout mice (kindlyprovided by D. Montag Leibniz, Institute for Neurobiology, German), andC57Bl/6 mice at the acute phase (days 10 to 15) of inflammation inducedby an aqueous dextran sodium sulfate solution, and analyzed for CHL1expression by flow cytometry analysis (FACSCalibur (BD)) usingAnti-Mouse CHL-1/L1CAM-2 Monoclonal Antibody (R&D Systems, Inc.) and APCgoat anti-rat IgG (BioLegend, Inc.: 405407). The expression of CHL1 onpodoplanin-positive fibroblasts was shown. The results were as shown inFIG. 3.

As shown in FIG. 3, the expression of CHL1 on cell surface was confirmedat the acute phase (days 10 to 15) as compared with the results of flowcytometry analysis on the normal (day 0) and CHL1-knockout (KO) mice.This demonstrated that Chl1 is expressed on a cell membrane at the timeof inflammation.

(D) Next, the expression of Chl1 was confirmed using a mouse largeintestine tissue in which chronic inflammation was induced, and a humanCrohn disease large intestine sample.

The large intestine was collected from each of normal COL1a2-GFPtg/+C57Bl/6 mice and COL1a2-GFP tg/+C57Bl/6 mice having chronicenteritis, and then fixed in 4% PFA, which was subsequently replacedwith 10% or 20% sucrose. Frozen tissues were prepared from the obtainedtissues using an embedding medium for frozen tissue section preparation(Tissue-Tek O.C.T. Compound). Sliced sections were prepared from thefrozen tissues, stained with Anti-Mouse CHL-1/L1CAM-2 MonoclonalAntibody (R&D Systems, Inc.), Goat anti human IgG (H+L) secondaryantibody, Alexa 647 conjugate (Life Technologies Corp.: A21445), andDAPI (nucleus), and observed under a fluorescence microscope (KeyenceCorp.).

The human Crohn disease large intestine sample and a sample of a healthyhuman subject (kindly provided by Hideki Iizima, Osaka University,Graduate School of Medicine, Department of Gastroenterology andHepatology) were subjected to the experiment according to the followingprotocol.

1. Activation using Retrievagen A (BD: 550524)

2. Blocking with Anti-human Fc block (ebio 14-9161-73 mouse IgG2a) (roomtemperature, 30 min)

3. Overnight incubation with anti-human CHL1 rabbit polyclonal antibody(Abcam PLC: ab106269) as a primary antibody (low-temperature room), 100μL/slides

4. Washing for 5 minutes 2 times using PBS under gentle shakingconditions

5. Overnight incubation with anti-rabbit Alexa 594 donkey antibody(BioLegend, Inc.: 406405) as a secondary antibody (low-temperatureroom), 100 μL/slides

6. Washing for 5 minutes 2 times using PBS under gentle shakingconditions

7. Staining with DAPI (room temperature, 20 min, 100 μL/slides)

8. Washing for 5 minutes 2 times using PBS under gentle shakingconditions

9. Mounting with Fluoromount

The results were as shown in FIG. 4. As shown in the upper panels ofFIG. 4, at the chronic phase (upper right panel of FIG. 4), the CHL1molecule was strongly expressed in type I collagen-producing cells(Col1) present in the lamina propria and a submucosal layer. On theother hand, the expression of the CHL1 molecule was hardly observed inthe normal tissue (upper left panel of FIG. 4).

Next, immune response in the inflammation sample was confirmed. Theresults were as shown in the lower panels of FIG. 4. As shown in thelower panels of FIG. 4, the expression of the CHL1 protein was confirmedin the human Crohn disease large intestine sample (Crohn disease sampleNos. CD-13 and CD-68). On the other hand, the expression was unable tobe observed in the healthy human subject (HV-70). From these results,the accumulation of the CHL1 protein throughout the tissue was able tobe confirmed in the Crohn disease large intestine sample.

Example 4: Role of CHL1 in Repair of Damaged Muscle Fiber

In this Example, the physiological functions of CHL1 were examined.

Lamina propria cells of the large intestine were isolated from each ofwild-type (WT) and CHL1 KO mice having acute enteritis by the methoddescribed above, and cultured in a medium having the composition shownin the table below, and adherent cells were collected to obtain largeintestine subepithelial myofibroblasts.

TABLE 3 Manufacturer Concentration GlutaMAX ™ Supplement GIBCO ×1Recombinant Murine EGF Peprotech 20 ng/ml apo-Transferrin from HumanNacalai Tesque 10 μg/ml Insulin from bovine pancreas Sigma 0.25 U/ml

The large intestine subepithelial myofibroblasts derived from each ofthe WT and CHL1 KO mice were inoculated to a 6 cm dish, followed byscratch assay of damaging the cells using the tip of a 100 μL pipette.The manner of recovery of the cells was observed before the start, 14hours later, and 19 hours later. The results were as shown in FIG. 5.

As shown in FIG. 5, the recovery of the damage site was alreadyconfirmed in the WT mouse 14 hours later, whereas the knockout of CHL1was found to drastically delay the recovery. This indicated thatCHL1-knockout fibroblasts have reduced activity.

The role of CHL1 was further analyzed using an enteritis model preparedby the administration of dextran sodium sulfate. Specifically, anaqueous dextran sodium sulfate solution (2.25%) was administered bydrinking to wild-type C57Bl/6 mice (n=4) and CHL1 KO mice (n=6) for 5days. Then, their body weights were measured. On day 18, the largeintestine was harvested from each mouse, and fixed in PFA. Then,paraffin sections were prepared and stained with hematoxylin-eosin. CHLWT and CHL KO mice of COL1a2-GFP background were prepared and treatedwith an aqueous dextran sodium sulfate solution. Then, their largeintestine tissues were stained with an anti-EpCAM antibody, ananti-actin antibody, and monoclonal anti-α-smooth muscle actinantibody-Cy3™ labeled (Sigma-Aldrich Co. LLC, C6198-100UL) and observed.The results were as shown in FIG. 6.

As shown in FIG. 6, the reduced activity of large intestine fibroblastsand the delayed healing of the mucosa were observed in the knockoutmouse congenitally deficient in CHL1 (FIGS. 6B and 6C). Also, bodyweight recovery was delayed in the CHL1-deficient knockout mouse ascompared with the wild type (FIG. 6A). FIG. 6C shows that theaccumulation levels of epithelial cells (stained with EpCAM) andfibroblasts (stained with aSMA) in tissues are lowered. This result isdata supporting the delay of tissue repair due to the reduced activityof fibroblasts.

Furthermore, frozen large intestine tissues of normal COL1a2-GFPtg/+C57Bl/6 mice or COL1a2-GFP tg/+C57Bl/6 mice having enteritis werestained with mouse CHL-1 protein (Fc tag) (Sino Biological Inc)-goatanti-human IgG (H+L) secondary antibody, Alexa 647 labeled (LifeTechnologies Corp.: A21445) (red), and DAPI (nucleus), and observedunder a fluorescence microscope (Keyence Corp.). The results were asshown in the photographs of the left panels of FIG. 7. As shown in FIG.7, CHL1 associated with an intestinal subepithelial myofibroblast and acell localized in a submucosal tissue where fibrosis would occur, in theintestinal tissue in which enteritis was induced (left photographs ofFIG. 7).

CD45-negative EpCAM-negative (i.e., fractions that were neitherepithelial cells nor immunocytes) lamina propria cells of the largeintestine were isolated from normal C57Bl/6 mice, stained withantibodies to podoplanin (gp38) and CD146 (BioLegend, Inc.), and gatedinto R1, R2, R3, R4, and R5 (see the right panels of FIG. 7). Each ofthe fractions R1 to R5 was analyzed by FACS using CHL-1 protein (Fc tag)(Sino Biological Inc)-goat anti-human IgG (H+L) secondary antibody Alexa647 labeled (Life Technologies Corp.: A21445). The results were as shownin FIG. 8.

As shown in FIG. 8, as a result of further gating the CD45-negativeEpCAM-negative fractions into R1 to R5 on the basis of gp38 and CD146,and reacting the CHL1 protein with each of the fractions, a cell groupassociating with CHL1 was confirmed in the fraction R3. The fraction R3is known as a fraction of myofibroblasts. This suggested that CHL1functions on myofibroblasts.

Example 5: Preparation of Anti-CHL1 Monoclonal Antibody and FunctionalAnalysis of Obtained Antibody

Mouse CHL1 gene (mChl1) was cloned into pIRES2-EGFP vector by PCR usingPhusion (Thermo Fisher Scientific Inc.: F530L). Y3Ag cells (ratmacrophage cell line) were transfected with mChl1 pIRES2-EGFP byelectroporation, and four 7-week-old female or male SD rats (CLEA Japan,Inc.) were immunized from their footpads and tail roots with a mixtureof the cells with TiterMax Gold (Funakoshi Co., Ltd.: G-1X5). After 3 to8 immunizations, inguinal lymph nodes or iliac lymph nodes wereisolated, and their cells were fused with AG8 myeloma cells usingPEG1500 (Roche: 10783641001). The obtained hybridomas were screened inHAT medium (DS Pharma Biomedical Co., Ltd.: 16-808-49) or HT medium (DSPharma Biomedical Co., Ltd.: 16-809-49) under conditions supplementedwith BM condimed H1 (Roche: 11088947001). The culture supernatants werecollected and reacted with HEK293 cells transfected with mChl1pIRES2-EGFP. Then, antibody titers in the supernatants were studied byFACS analysis using APC goat anti-Rat IgG (BioLegend, Inc.: 405407). Asshown in FIG. 9, the obtained antibody recognized the CHL1 protein oncell surface.

The hybridoma clone 336 obtained as described above wasintraperitoneally administered at approximately 5×10⁶ cells to a Balb/cnude mouse (female, 7 weeks old, CLEA Japan, Inc.), and its asciticfluid was collected. The antibody was purified from the ascitic fluidusing protein G and used in subsequent research.

Next, the activity of the obtained antibody was evaluated. As forinhibitory activity, lamina propria cells of the large intestine werecollected and then reacted at 2×10⁶ cells with 50 ng/50 μl CHL-1 protein(Fc tag) (Sino Biological Inc) at 4° C. for 30 minutes. For thisreaction, 1 μg/50 μl antibody to CHL1 (336) was added. Then, theinhibition of the adsorption reaction of the CHL-1 protein was verifiedby flow cytometry using goat anti-human IgG (H+L) secondary antibody,Alexa 647 conjugate (Life Technologies Corp.: A21445). The results wereas shown in the upper and lower left panels of FIG. 10.

As shown in the left panels of FIG. 10, in the absence of the 336antibody, the lamina propria cell of the large intestine bound to CHL1,and the Fc tag on cell surface was able to be detected with the antibody(left upper panel of FIG. 10). On the other hand, in the presence of the336 antibody, the binding between the lamina propria cell of the largeintestine and the CHL1 protein was blocked by the 336 antibody (leftlower panel of FIG. 10). Likewise, the 336 antibody inhibited thebinding of the CHL1 protein to the lamina propria cell of the largeintestine in the presence of 75 ng of CHL1-Fc (FIG. 10, right).

The amino acid sequence of the heavy chain variable region and the aminoacid sequence of the light chain variable region of the obtained 336antibody will be shown below. CDR-H1 to -H3 represent CDR1 to CDR3,respectively, of the heavy chain variable region (SEQ ID NOs: 1 to 3,respectively). CDR-L1 to -L3 represent CDR1 to CDR3, respectively, ofthe light chain variable region (SEQ ID NOs: 5 to 7, respectively).

The heavy chain variable region of the 336 antibody has a signalsequence (MKCRWIILFLMAVATGVNS; SEQ ID NO: 9) at its N terminus, thedescription of which is omitted below. The light chain variable regionof the 336 antibody has a signal sequence (MDFRVQIFSFLLVSITVIVSSG; SEQID NO: 10) at its N terminus, the description of which is omitted below.

{Formula 1}

336 antibody heavy chain variable region (SEQ ID NO: 4):

336 antibody heavy chain variable region (SEQ ID NO: 4): Heavy chain[Formula 1]

336 antibody light chain variable region (SEQ ID NO: 8): Light chain[Formula 2]

{Formula 2}336 antibody light chain variable region (SEQ ID NO: 8):

In an in vivo inhibition experiment, enteritis was induced in 8-week-oldmale C57Bl/6 mice (CLEA Japan, Inc.) using 2.25% aqueous dextran sodiumsulfate solution. The 336 antibody (n=4) or a control antibody(polyclonal rat IgG; Bio X Cell: BE0094) (n=4) was intraperitoneallyadministered at 250 μg/dose on consecutive days from day 6 to day 10. Asfor change in body weight, their body weights were measured around 16:00every day. On day 11, the mice were dissected. Typical photographs aboutthe large intestine and HE (hematoxylin-eosin)-stained large intestineare shown. The results were as shown in FIG. 11.

As shown in FIG. 11, the 336 antibody delayed recovery from inflammationat the acute phase (left graph of FIG. 11). The results of HE stainingshown in the right lower photograph of FIG. 11 also shows that the 336antibody delayed recovery from inflammation at the acute phase. Thisdemonstrated that an antibody that can block the binding of the CHL1protein to a receptor on a cell membrane can suppress inflammation.

Example 6: Testing of Inflammation by Using CHL1 Expression Level asIndex

Chronic enteritis (fibrosis) was induced in C57Bl/6 wild-type mice byrepeated free drinking of 2.25% to 2.5% aqueous dextran sodium sulfatesolution. On days 10 to 15, days 60 to 70, day 100, day 120, and 130 theCHL1 expression of fibroblasts in the lamina propria of the largeintestine was analyzed by FACS. The CHL1 expression was analyzed by flowcytometry using anti-mouse CHL-1/L1CAM-2 monoclonal antibody (R&DSystems, Inc.)-APC goat anti-rat IgG (BioLegend, Inc.: 405407) andFACSCalibur (BD). The cells were labeled with antibodies to a blood cellmarker CD45 and a fibroblast marker podoplanin. Then, CD45-negativepodoplanin-positive fibroblasts were selected and analyzed for theexpression of CHL1 on cell surface. The results were as shown in FIG.12.

A shown in FIG. 12, it was demonstrated that neutrophil invasion servingas an index for acute inflammation was reduced while the expression wasmaintained even at the chronic phase of 60 days after the induction ofenteritis. The expression of the CHL1 protein at the chronic phase canbe used as an index for cell fibrosis.

Feces was harvested from mice having acute (n=12) or chronicinflammation (n=16) by use of an aqueous dextran sodium sulfatesolution, and untreated mice (n=13), and a CHL1 level in the feces wasanalyzed. The experimental approach will be described below.

Day 1

1. A 96-well plate is coated by overnight incubation at 4° C. in thepresence of the purified 336 antibody (1 μg/ml is added at 100 μL/well).

Day 2

1. The plate is washed three times with a washing buffer solution (0.05%Tween-PBS).

2. A blocking buffer solution (PBS containing 1% BSA) is added thereto(300 μL/well), followed by incubation at room temperature for at least 1hour.

3. The plate is washed three times with a washing buffer solution.

4. 100 μl of a sample is added to each well (1 mg/10 μL PBS, and theplate is vortexed at 4° C. for 30 minutes and centrifuged at 15000 rpm(15 min), followed by the collection of a supernatant.

Overnight

Day 3

1. The plate is washed three times with a washing buffer solution.

2. The biotinylated 336 antibody is added (detection Ab: stock 1 mg/mldiluting solution: reagent diluent 1% BSA in PBS) (1 μg/ml is added at100 μL/well), followed by incubation at room temperature for 2 hours.

3. The plate is washed three times with a washing buffer solution.

4. Streptavidin-HRP (R&D Systems, Inc., lot #310801/Part #893975)(dilution ratio: 1:40, 100 μL/well) is added, followed by incubation for2 hours.

5. The plate is washed three times with a washing buffer solution.

6. A HRP substrate is added (100 μl/well), followed by incubation for 45minutes.

7. A reaction stopping solution (50 μL of H₂SO₄) is added.

8. Absorbance is measured (450 nm/570 nm).

The results were as shown in FIG. 13. As shown in FIG. 13, the CHL1level in the feces was statistically significantly higher in the mousegroup with acute or chronic inflammation than that in usual mice. Thisindicated that the presence or absence of inflammation may be determinedby measuring the protein level of CHL1 using feces. These results alsoindicated that CHL1 is capable of functioning as a secreted factor.

Example 7: Therapeutic Significance of Antibody to CHL1 in FibrosisInduction Process

In this Example, the role of an antibody to CHL1 in a fibrosis inductionprocess after acute inflammation was examined.

To mice with intestinal fibrosis induced by the repeated free drinkingof an aqueous dextran sodium sulfate solution, the 336 antibody (250μg/dose) was intraperitoneally administered on consecutive days when themice recovered from weight loss (days 56 to 66) after the third run ofthe repeated free drinking. Polyclonal rat IgG (Bio X Cell: BE0094) wasintraperitoneally administered as a control antibody. On day 67 or 68,the mice were dissected, and their large intestine tissues werecollected. Then, paraffin sliced sections were prepared. Collagendeposition and the accumulation of activated fibroblasts andmyofibroblasts were analyzed by Azan staining or staining with α-SmoothMuscle—Cy3™ antibody, Mouse monoclonal clone 1A4, purified fromhybridoma cell culture (Sigma-Aldrich Co. LLC, C6198-100UL) (red) andDAPI (nucleus; blue). The results were as shown in FIG. 14.

As shown in FIG. 14, the 336 antibody, a monoclonal antibody to CHL1,suppressed collagen deposition in the tissue after acute inflammation,and suppressed fibroblast activation.

Examples described above indicated that the antibody to CHL1 suppressesinflammation caused by CHL1. Examples described above also demonstratedthat when inflammation is suppressed at the chronic phase, collagendeposition and fibroblast activation can be suppressed, and fibrosis inan inflammatory tissue can thereby be suppressed.

SEQ ID NO: 1: Amino acid sequence of the heavy chain CDR1 of a 336antibody

SEQ ID NO: 2: Amino acid sequence of the heavy chain CDR2 of the 336antibody

SEQ ID NO: 3: Amino acid sequence of the heavy chain CDR3 of the 336antibody

SEQ ID NO: 4: Amino acid sequence of the heavy chain variable region ofthe 336 antibody

SEQ ID NO: 5: Amino acid sequence of the light chain CDR1 of the 336antibody

SEQ ID NO: 6: Amino acid sequence of the light chain CDR2 of the 336antibody

SEQ ID NO: 7: Amino acid sequence of the light chain CDR3 of the 336antibody

SEQ ID NO: 8: Amino acid sequence of the light chain variable region ofthe 336 antibody

The invention claimed is:
 1. A monoclonal antibody that binds to humanCHL1 protein, or an antigen-binding fragment thereof, wherein theantibody or antigen-binding fragment comprises: a heavy chain variableregion comprising a heavy chain CDR1 comprising SEQ ID NO: 1, a heavychain CDR2 comprising SEQ ID NO: 2, and a heavy chain CDR3 comprisingSEQ ID NO: 3; and a light chain variable region comprising a light chainCDR1 comprising SEQ ID NO: 5, a light chain CDR2 comprising SEQ ID NO:6, and a light chain CDR3 comprising SEQ ID NO:
 7. 2. A monoclonalantibody or the antigen-binding fragment thereof that binds to humanCHL1 protein, comprising a heavy chain variable region comprising SEQ IDNO: 4 and a light chain variable region comprising SEQ ID NO:
 8. 3. Apharmaceutical composition comprising an antibody or an antigen-bindingfragment thereof according to claim 1 and a pharmaceutically acceptablecarrier.
 4. A pharmaceutical composition comprising an antibody or anantigen-binding fragment thereof according to claim 2 and apharmaceutically acceptable carrier.